2003 Buick Rendezvous air conditioning

2003 Buick Rendezvous mileage 28,000. The problem I seem to be having is with the air conditioning, the car has been sitting for about a year and the R-12 Freon leaked out so I released all the remaining Freon so it won't get mixed with the R-134. I went to buy a conversion kit to convert the R-12 to R-134 I put 2 cans of Freon to activate the system and then 1 can of compressor oil, but then I checked the pressure and it reads between the blue and yellow, now does that mean there is too much pressure instead of Freon? After I completed the conversion and checked for cold air coming out of the vents, it wasn't even cold at all it was just cool, the thicker diameter hose which is supposed to be cold and it is. I hooked up the pressure gauge, as I watched it I released the pressure out of the high side line of the system and the gauge reads now in the blue, which means its full right? The lines coming from the compress or, one is hot and one is cold that's what it's supposed to be right? I think I know what happened after the first two times that I tried to fill the system it was trying to stop the leaking of the Freon, after it leaked out some I didn't check the pressure to see what was remaining in the system so I put in more Freon, I think that's why its not getting as cold, can you tell me how to get my air conditioner back to cold? Brrrr.